<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
</head>
<body>

</body>
<script>
    // 在js中 函数是一等公民!!!!
    var sum = new Function('a', 'b', 'return a + b');
    var res = sum(2, 6)
    console.log(res)
</script>
</html>